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Go catless with boost

Chainsaw

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you wont be able to see all the bore especially at the very top. only way to be absolutely sure is to pull the head.
An articulating borescope will show the top of the bore.
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DavidHuff

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Stock whipple tune, 3.625 pulley, 93 octane....kooks high flow cats started failing after a few hundred miles ( sulfur smell after WOT pulls). I spoke with Kooks directly and was advised their standard high flow cats are NOT intended for forced induction applications. I gutted them and car runs way better.
You did not get a CEL On after you gutted the cats on your Whipple Tune?
 
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stang17

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You did not get a CEL On after you gutted the cats on your Whipple Tune?
CEL came on after about 200 miles of driving with the headers and high flow cats. Some guys get the CEL with the cats, some don't. I would use the whipple flare to clear the code, but it would come back on after about 40 miles.

When we gutted the cats the CEL would stay on. I ended up having my tuner use HP tuners to tweak the stock whipple tune to turn off the rear 02 sensors to keep the CEL from coming on.

Some other changes were made to PE, torque tables, per cylinder knock detection, etc to help smooth out the whipple tune. If you have HP Tuners, I can send you a copy of my tune if you would like. Mods in Sig.
 

Sean@LethalPerformance

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Yeah, the Kooks green cats are really the only catalytic converters thats safe to on a car with boost. Their green cats are good to 950 HP if I recall correctly.
 

Dominant1

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Yeah, the Kooks green cats are really the only catalytic converters thats safe to on a car with boost. Their green cats are good to 950 HP if I recall correctly.
Yeah but they’re $369 each and should be welded in place. Catless is cheaper and makes more sound and power. Only drawback is the stink..
 

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stang17

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I personally though the car had more stink to it when I had the cats on. When cat protection kicks in and dumps the excess fuel, you get the rotten egg/sulfur smell.

Without the cats, you may get a slight fuel smell if your sitting at idle and the wind is blowing towards the front of the car while your windows are down.

As long as your moving or have the windows up you don't smell anything. Well at least this has been my personal experience so far.
 

Performance nut

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Yeah but they’re $369 each and should be welded in place. Catless is cheaper and makes more sound and power. Only drawback is the stink..
That's like saying the only drawback to castration is you lose a little weight and become liberal. Car without cats smells like crap and it doesn't take long to stink it up. You guys without cats are the stinky kid in class. I'm not talking "I forgot my deodorant today" smell, talking "been going to the gym for a week without a shower" funk.

Green cats aren't as good as the stock cats but it is way better than none at all. Folks will drop $10k+ for a FI system but can't be bothered with <$1k emissions equipment. Crazy logic.

If your car is totally track duty, yeah take them off because it isn't worth it. If it is occasional track duty street car, do us all a favor and put some cats on the thing.
 

TX-Ripper

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Nothing worth than sitting behind that in a staging lane...
 

Joe 5.0

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We removed the centers of my kooks cats. Benefits of a cat delete with the appearance of a cat.

Car drives noticeably better and no more sulfur smell after WOT pulls.

Considering adding some vibrant performace 3 inch resonators to get rid of the new found raspiness byproduct of no cats.
Shot in the dark, but do you have a photo of cats?
 

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Excelerater

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I have ARH cats with my whipple over a year
no issues.....Maybe I should gut mine,anyone do that ?

How hard to do ?
 

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I have ARH cats with my whipple over a year
no issues.....Maybe I should gut mine,anyone do that ?

How hard to do ?
Dont gut just get the ARH connection pipes .. beefcake got mine for me $339 shipped and with them i retain my arh liftime warranty..
 

jasonstang

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Looks like just poorly made aftermarket cats. Factory cats are not this kind of construction.
 

GreenS550

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Removing cats on a SC car with headers equals LOUD. Been there, done that. I wouldn't do it. Too loud. Of course, if that is what you want, then OK.:cool:
 

Crackerjack17

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Removing cats on a SC car with headers equals LOUD. Been there, done that. I wouldn't do it. Too loud. Of course, if that is what you want, then OK.:cool:
Not true! If you have the right exhaust. I installed the varex exhaust. It has the valves at the end of the mufflers. When closed its almost quieter than stock. Open its loud behind the car, but not inside.
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